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Products => Test Equipment => Topic started by: johncprice on January 30, 2018, 09:55:58 pm

Title: Lecroy LC684 (DDA-125) screen brightness
Post by: johncprice on January 30, 2018, 09:55:58 pm

I just got a Lecroy DDA-125 (same as LC684AXL, I believe) from Ebay in the US. It seems I got lucky and everything is working as expected. In my home lab it is replacing a Tek 7904, so this thing is quite an improvement! The only fault I can find with it is that the screen is not very bright. Does anyone know if there is a way to fix that? Maybe there is a backlight tube that can be replaced?

Title: Re: Lecroy LC684 (DDA-125) screen brightness
Post by: nctnico on January 30, 2018, 10:04:45 pm

If it has an LCD screen you can try CFL replacements which use LEDs.
https://www.ebay.com/itm/385mm-LED-Backlight-Strip-Kit-CCFL-LCD-Screen-to-LED-Monitor-DC-10-30V-D7W8-U5X7/182948771911?epid=20010951805 (https://www.ebay.com/itm/385mm-LED-Backlight-Strip-Kit-CCFL-LCD-Screen-to-LED-Monitor-DC-10-30V-D7W8-U5X7/182948771911?epid=20010951805)

You'll have to adjust the current through the LEDs though after cutting the strip to the right length. There are current sensing resistors on the board which are easy to identify.

Title: Re: Lecroy LC684 (DDA-125) screen brightness
Post by: johncprice on January 30, 2018, 11:36:05 pm

Thanks for the reply. I just found a Youtube video showing a repair of a DDA-125 screen. It is a Sharp LQ10D367 10.4" TFT module, and new backlight assemblies for it are available for $15 on Ebay and Amazon. So I will give one of those a try.

Title: Re: Lecroy LC684 (DDA-125) screen brightness
Post by: eb4eqa on January 30, 2018, 11:40:22 pm

If you want tongo thru the trouble, installing a LED backlight is not difficult and will provide illumination.

http://www.rbarrios.com/projects/LCD2LED/ (http://www.rbarrios.com/projects/LCD2LED/)

Roberto